Lumbar Facet Arthroplasty Versus Fusion for Grade-I Degenerative Spondylolisthesis with Stenosis: A Prospective Randomized Controlled Trial

The Future of Motion Preservation and Arthroplasty in the Degenerative Lumbar Spine

The lumbar degenerative cascade is a pathological process that affects most of the aging adult population and has significant negative economic consequences. Lumbar fusion surgery remains a mainstay of treatment for refractory degenerative disease but carries significant long-term consequences. More recently, lumbar arthroplasty and motion-sparing technology has become an increasingly popular alternative surgical option in carefully indicated patients. Arthroplasty technology carries the theoretical benefits of spinal segment motion preservation and decreased degeneration of adjacent segments as compared to traditional fusion procedures. This article will review the lumbar degenerative cascade and its related anatomic considerations, current management strategies and the challenges surrounding lumbar spinal fusion, including adjacent segment disease. This article will also review the theoretical benefits of lumbar arthroplasty and motion preservation. Furthermore, this paper will highlight the current state of lumbar arthroplasty, including current concepts of implant design, limitations, outcomes and ongoing development. It will review the development and current state of artificial disk arthroplasty, total joint arthroplasty and posterior column motion-preserving implants, including flexible rods and facet joint replacement.

Analyses of proximal adjacent segment degeneration and prognostic factors after lumbar fusion surgery: study based on proximal facet joint angle

OBJECTIVE

Lumbar fusion surgery is a common procedure for treating various degenerative spinal conditions. However, the incidence of proximal adjacent segment degeneration (PASD) remains a concern. This study aimed to investigate the effect of proximal facet joint angle (FJA) on PASD and then identify factors that influence prognosis after lumbar fusion surgery.

METHODS

In this retrospective study, the cases of 192 patients who underwent lumbar fusion surgery between January 2020 and June 2022 were analysed. Patients were classified in accordance with their baseline proximal FJA into the high (≥ 40°) and low (< 40°) FJA groups. Prognosis was evaluated during the last follow-up by using clinical, imaging and functional recovery criteria. PASD was assessed using Weishaupt criteria, and imaging parameters were measured on postoperative computed tomography (CT) reconstructions. Statistical analyses, including univariate and multivariate logistic regression, were performed to identify prognostic factors. Receiver operating characteristic (ROC) curves were used to assess predictive value.

RESULTS

The high FJA group exhibited significantly higher rates of PASD compared with the low FJA group (P < 0.001). No significant differences were observed in sex, age, body mass index (BMI) or follow-up duration between the two groups. Poor prognosis was associated with higher BMI, larger FJA and wider facet joint diameter. Logistic regression analysis identified BMI (odds ratio [OR] = 1.801, P = 0.001), FJA (OR = 6.320, P < 0.001) and facet joint sagittal (OR = 1.888, P < 0.001) and coronal (OR = 1.462, P < 0.001) diameters as independent predictors of poor prognosis. A smaller screw inclination angle was associated with better outcomes (OR = 0.907, P = 0.017). Joint ROC analysis underscored the significant predictive power of these factors (area under the curve = 0.881).

CONCLUSION

This study demonstrates that a larger proximal FJA is associated with increased PASD. It also identifies several prognostic factors that influence outcomes after lumbar fusion surgery. Patients with higher BMI, larger FJA and wider sagittal and coronal diameters are at increased risk for poor prognosis. These findings highlight the importance of comprehensive preoperative assessments to optimise surgical planning and improve outcomes in lumbar fusion surgery.